Low-voltage circuit breaker



, E. G. IOHNSON. LOW VOLTAGE CiHCU BREAKR. PPucmoN mw ou; x0. ma.

1,431,956, Panted Oct. 17, 1922.

Y z sains-guzzi x.

E. G. IOHNBUN.

LOW VOLTAGE CIRCUIT BREAKER.

APPucATlon msu ofc \o. 191s.

Panama 00L 111922.

2 SHEETS-SHEET 2.

Patented Oct. 17, 1922.

UNITED STATES PATENT OFFICE.

ERNEST o. JOHNSON. or WAVERLEY, MASSACHUSETTS, AssiGNOR, BY MESNEASSIGN- MENTS, To WESTINGHOUSE ELECTRIC a MANUFACTURING COMPANY, ACORPO- RATION 0F PENNSYLVANIA.

LOW-VOLTAGE CIRCUIT BREAKER.

Application tiled December l0, 1918.

To all whom it 'may concern.'

lle it known that I, Elixir. G. JOHNSON, a citizen of the United States,residing at Waverley, in the county of Middlesex and State ofMassachusetts, have invented new and useful Improvements in Low-VoltageCircuit Breakers, of which the following is :i specification.

This invention has for its object to provide a remote control switch andcircuit breaker, which is operative to break analternating currentcircuit upon decrease in po tential or failure of the alternatingcurrent.

On the accompanying drawing,

l"i rure 1 illustrates in front elevation a circuit breaker embodyingthe invention..

Figure 2 represents a vertical section through the san'ie.

Figure 3 illustrates in detail the latch mechanism which constitutes anovel feature of the circuit breaker.

Figure t is a diagrammatic view, showing certain of the operativeelements and the circuits on which they are located.

In many of its construetional d etails, the circuit breaker, which lhave illustrated upon the drawings as embodying thev present invention,is like the a paratus illustrated and described in Letters atent No.1,179,957, to Granville E. Palmer, dated April 18, 1916, and referencemay consequently be had thereto for a more detailed explanation ofcertain of the parts or elements to which shall but briefly refer in thefollowing specification..

The main Switch for the circuit, which in r igure -1 comprises the twolines 10 and 11, includes the stationary contacts 12, 13, and lliecooperating movable laminated brush contact members 16, 17. The faces 14and 15 of the stationary contacts 12 and 13 are arranged at an angle ofapproximately the members 16 and 1T likewise forming a right angle, soas to make proper contact with said faces. The brush contacts aresecured to but are insulated from a cross bar 18` secured to an arm orlever 20 movable about a pivot or shaft 19. The movable switch membersare moved into and out of contacting relation with the stationaryinembei's as the arm 20 is swung about its axis. 'llie lever 20 is movedto closed position b v a main solenoid magnet 24, the armature orplunger 25 of which is pivoted to the arin 2U bv a pin 2G. The lever isopened b v one Serial No. 266,151,

or more springs 22 coiled about the shaft 19 and engaged with the arm orlever. The solenoid 24 is placed in a branch circuit, for which currentis derived from the main circuit 10, 11. This branch circuit comprisesthe conductors a, b, c and cl, as shown by the diagram in Figure 4. Thisbranch circuit is closed by one instrumentality and automaticall openedby another, as will be explained. l `or closing the branch circuit tothc solenoids 24, a Solenoid magnet, comprising two solenoid coils 2,27, is placed in a second branch circuit, the conductors of which areindicated at e and f, this magnet being in multiple with the magnet 24.This branch circuit may extend to a remote point, and have a switch li,included therein to provide a remote Control for the main switch. Themagnet, comprising the coils 27, forms the subject-mattei' 4of anapplication of Granville E. Palmer, Serial No. 266,132, filed December10, 1918, per se and constitutes no separate feature of the presentinvention, so that any equivalent for it may be utilized. It isparticularly adapted for use in the present circuit bieaker because ofcertain characteristics which will be briefly referred to. Forcooperation with the solenoids 2T, there are two U-shaped members 28,29, arranged in opposition, and constituting together an armature, inwhich there is a complete magnetic circuit when an alternating currentof predetermined potential is passed through the solenoid coils. Each ofsaid members 28 and 29 has arms or plungers extending into the solenoidcoils, and which are brought into contact to form a complete magneticcircuit or field when the solenoid coils are excited b a current ofdesired potential. When suc i current is passing through the solenoids,the tivo-part armatnrefloats and produces no hum or chatter. 'lhe crossbar of the armature member 28 is provided with a lateral project-ion 30,upon which a movable contact member 31 (prop crly insulated therefrom)is mounted so as to make contact with and complete the eircuit throughtwo stationary spring contact incinhcrs 212. 32, arranged in the branchcircuit in which the main solenoid 24 is located. L\ssuiiiing that thesaid branch circuit is otherwise closed, it will be understood that.when the solenoids 27 are energized to cause the contact iuciiiber 3l tobe moved to active position, the main solenoid 24 is energized to movethe arm 2() from open to closed position, as shown in Figure El, therebymoving the main switch members lGA and li to closethe main circuitthrough the stationary contacts l2 and l-l. From the stationary contactmembers 13 the working circuit is indicated at g.

In order to break the branch circuit through the solenoid 24 as soon asit has performed its function, a supplementalor contactor switch isemployed, which is substantially like that described in the Palmerpatent hereinbefore referred to. This mechani'sm comprises a member orcontactor 33, adapted to be brought int-o electrical contact with thetwo stationary` members 34, 34, which are respectively connected to theconductors c and d in the shunt or branch circuit. The movable member 33is operated by an arm pivoted upon the shaft 19. This arm, which isindicated at 35, is provided with a pivoted extension 36, hung theretoby a pin '37. A coiled spring 38 is inter posed between the extensionand the arm, so as to permit one to yield relatively to the other and topermit a certain flexibility of play of the contactor 33. A coiledspring 39,'between the lever 35 and a shoulder on the arm'20, tends tothrow the arm 35 and the contactor'33` downwardly, so that the latterwill rest upon thestops 40. The arm 20, which is bifurcated at its lowerpivoted end, is provided with a bridge or cross bar 41, one edge ofwhich is adapted to engage the lever 35, as the arm 20 moves from itsclosed position'in Figure 3 to its open position in Figu1'e'2, and toswing said lever about its pivot', so as to bring the contactor ormember 33 in circuit-closing position in enga ment with the contacts 34.W hen the said ever has reached this position, it may be there held by ahooked latch 42. This latch is springtensioned by a coil spring 43normally to swing to the right, in Figures 2 and 3, so as to engage afnver 44 projecting from the pivoted end o? the lever 35. The hub of thelatch 42 is pivoted upon a cross shaft 45. The latch is so located inreference to the arm 20 that, as the latter reaches its closed position`the cross bar 4l thereon will exert a camming action on the latch 42 toswing it outwardly and cause it to release the lever 35, upon which, ofcourse, the springr 39 will force the lever downA wardly. The describedconstruction und arrangement of parts are for the purpose of ensuringthat the contactor 33 is, when the main switch is open, in electricalcontact with the contactmembers 34 of the branch circuit 24. and thereremains until the lever 2U has almost reached its closed position. .\sthe arm 20 and the main switch members approach their closed positions.the hitch 42 is moved to release the` lercr 35. which switch members andthe arm 2U are moved to closed position b \f the solenoid 24, actingupon the plunger h', and l hun also cx plained that, as Soon :is thorapproximately rcarh this position, thc brunch circuit through SuidSolenoid is luolien. 'l'o hohl the main switch members in their closedposition, I employ a novel lock. which is automatically operated by thesolenoid 24 or its equivalent to loclt the lever 2U in closed position,and which is automatically released when the circuit through thesolenoids 2T fails or reaches a predetermined low voltage. Thislocking,Ir mechanism comprises :L bellcrank lever, indicated as a wholeat 4G, and having arms 47 and 48, as shown in Figures 2 and 3. The arm4S is formed of soft iron (laminated, if desired), so as to constitute asecond armature for the. solenoid magnet 24, It extends downwardlyacross the end of the coil and plays in a slot 49 in the plunger 25. Thearm 47 projects across the up per end of the arm 2t), and it isbifurcated or yoke-shaped, between the arms of which there is a pin 50and a roller 51. In the end of the arm 20 there is a spring-pressedbeveled dog;` 52, which` when the arm 2() is in its closed position, isadapted to engagithe roll 5l on the arm 47, and thus hold the arm 2O andthe main switch n'ienihcrs in closed position. The. bell'crank lever 4Gis fulcrumed upon a pivot 53, which is so located t-hat, when the arm 4?is in the posiv tion shown in Figure 3, the thrust of the doler 52against the roll :'1 on the arm 4T is resisted positively, and the arm2O is held in its locked position. When the main switch is open and thearm 20 is in thi.l position shown in Fiuure 2, the arm 47 is so locatedthat the dbg could more thereunder without touching it, should the arm20 be swung to the right. When the circuit through the solenoid 24 isclosed, both the plunger 25 and the armature 48 are moved.

`and the arm 47 is swung down to its locltinTcr position into the pathof movement of the dog. so as to engage the dog 52- after thtl latterhas passed it and lock the arm 20 and the main switch members in theirclosed position. It will thus be seen that I have provided a mechanicallock for the main switch. which. b v its mechanical action. holds themain switch closed, but which is magnet-ically moved from its inactiveor inoperative position to its active or operative lockingr positionjust prior to the closing of the main switch. The loch is released uponfailurc of current through the solenoids 27, or when thc potential hasdropped below a certain \'olt age, To this end. the bell-Granit 4; hasau :irm or tail .34, which projects lo the right lllU in Figure 3, andwhich is ada ted to be engaged by a member depen ing from the armature2S of the s olenoids 2T. This memlu'r 55 is shown as in the form of: ascrew, so that it may be adjusted longitudinally, and it is screwed intothe projection 30. The parts are so located that, when the armature. 2Sis released by the solenoids 27. thc member 55, in dropping, will strikethe arm :'14 a hammer blow and lift the locking arm 47 so as to releasethe dog 52 and permit the arm 2() to be moved to its open position,thereby opening the main switch members.

It will of course be understood that the various parts are properlyinsulated from each other, where insulation may be needed, and that theyare all suitably mounted upon a back-board of suitable material. Thevarious conductors of the main, working and branch circuits are broughtto proper terminals where they may be easily connected, as described.

In operation, assuming that an alternating current ofpredeterminedpotential is supplied from a suitable source to the maincir; cuit and that the main switch is closed to the working circuit g,current is supplied by the branch circuit f to the solenoids 27. Thetwo-part armature thereof is in its operative position with the armature28, 29 oatinfr in the magnetic field and holding the mem er 55 in araised position. At this time, the lock 47 is locking the arm 20 and themain switch movable members in their closed positions; and the contactermember 33 is in the position shown in Figure 3, so that no current ispassing through the main solenoid 24. Assuming that the currentgradually drops in potential, the following results occur. Due to lossin energy, thearmature 28, 29, moves downwardly until the member 29rests upon the top of the coils 27, where the parts remain during thefurther decrease in potential, until such loss in energy occurs that theweight of the member 28 causes it to be released. The member 28-has beenheld against movement during this gradual decrease in potential becausethe two members 2S and 29 constitute magnets, which remain in contact bytheir mutual magnetic attraction. As soon as the magnetic forcedecreases, as stated, so that the weight of the member 28 causes it tobe released, it suddenly drops, and, by reason of its acquired momentum,the screw 55 strikes the arm 54 with a hammer blow, thereby lifting thelock 47, whereupon the arm 20 and the movable members of the main switchare immediately swung to open position. As the arm 20 moves to openposition, 1t moves the supplemental switch member 33 to closed position.as previously explained, and the latch 42 holds it in such closedposition. Consequently, upon restoration of current of proper potentialin the main circuit and in the branch circuit which includes thesolenoids 27, the armature 28 is raised to bring the switch member 31into contact with the contacts 32, so as to close the branch circuit ofthe main solenoid 24, thereby causing tlic main switch to be closed, aspreviously dcscribed.

The main switch is electro-magnetica]ly closed and is self-opening. Theelectro-mag- 'net which operates the main switch is in a normally opencircuit containing two supplemental switches, one of which is controlled by said electro-magnet, and the other of which is controlled byan electro-magnet in a normally closed branch circuit at all times inClosed connection with the main circuit. The main switch is lockedmechanically in closed position by a mechanical lock. which, however, iselectro-magnetically actuated by the same electro-magnet which closesthe main switch, and which 1s tripped by the armature of the magnetlocated in the normally closed branch circuit.

In the embodiment of the invention herein illustrated and described, Ihave accomplished several important results by novel mechanism. The mainswitch is held in its closed position mechanically, without the use ofsprings, this being achieved by the lock 47 which is engaged by the dog52. To

`release the main switch and afford it an opportunity for self-opening,the lock is swung about its pivot so as to disengage it from the dog. The lock itself is held rigidly in Iock mg position by the armature 48and electromagnet 24, only during the closing move- `ment of the mainswitch, since it is only during this movement that the electromagnet isenergized. As soon as this movement ceases, the current in magnet 24 iscut off rly the auxiliary circuit breaker 33, 34, 34.

he breaking of the circuit through the ma net 24 does not have anyeffect on the loci, which continues mechanically to hold the main switchclosed until such time as the magnet 27, due to current failure to apredetermined point, permits the armature 28 to drop, and. with a hammerblow, to strike the tail 54 of the lock and move the locking end thereofout of the path of the dog 52. The lock does not move or yield, when themain'switch is again being moved to closed position, since, as stated,it is then being held or located rigidly against movement, and hence thedog 52 is yieldingly mounted so that. in the final closing movement ofthe main switch, the dog yields or is pressed downwardly so as to rideunder the rigidly held lock. Hence of the two elements1 i. e. the dog onthe switch and the lock, one is moved or yields to permit the switch tobe completely closed, and the other is moved to permit the switch toopen without the necessity of the openin means (the armature overcomingt e yielding i means or spring which is essential to permit theswitch-closing operation. The power re- ,quired to close the switch maybe relatively great according to the size and weight of the movingrparts, whereas the power necessary to permit the switch to open shouldbe as small as possible, in order that the magnet 2, which is constantlyin circuit, should consume the least amount of current. Thus, inreleasing the switch, the mechanism is so constructed as to obviate thecompression or flexure of the spring which yields when the switch isbeing closed, and to provide for the movement of the lock to release thespring-tensioned dog. The time element is important, since the dog andthe lock must interlock instantly on the closing movement of the switch.in order to prevent any rebound of the switch and the movement of thcdog in the opposite or switch-opening direction. To secure this result,the dog `in moved endwise or longitudinally by the direct thrust of itsspring, and, after the end ol" the dog rides under the roller 51 on theloclr and yields in so doing, it is instantly forced endivise by itsspring behind the roller as soon as it passes under the axis of theroller. ln fact, the roller is rotated on its axis b v the dog as thelatter rides thereunder. The flat face of the dog lies against theroller and its end projects perpendiculai-ly only slightly beyond a lineconnecting the axes of the roller 51 and the pivot 53, when the lock ismechanically holding the .switch closed, and hence, as only a relativelyvery light blow of the amature 28 against the tail 54 of the lock isthus required to eect the release of the dog, the armature may be lightin weight and the magnet correspondingly small so as to consume aminilnum amount of current.

Haring thus explained the nature of my said invention, and described away of making and using the Samel although without attempting to setforth all of the forms in which it may be made or all of the modes ofits use, what I claim is 1. A loiv voltage circuit breaker comprising aself-opening main switch, a closing mechanism for the main switchinclud' an electro-magnet, a mechanical lock for holding said mainswitch closed, and operated to r:losed position by said electro-magnet,and means responsive to voltage variations in the line arranged to tripsaid lock mechanically and permit said main switch to open on failure ofline potential.

Q. A loiv Avoltage circuit breaker for use with :1 main circuit derivingits current from ii suitable source of potential, comprising :iSelf-openingr main switch, a normally open branch circuit including anelectroanagnet for closing the main switch, and a mechanical lock forsaid main Switch supported independently thereof and associated with andoperatively moved to locked position by said main-switch-closingelectro-magnet but Vheld mechanically in locked position.

3. A switch mechanism comprising a selfcpening switch, including amovable member, a lock for mechanically locking said member in closedposition, :in electro-mag net, an armature therefor operativelyconnected to said movable member, and a second armature thereforoperatively connected to said lock.

4. A low voltage circuit breaker comprising a self-openin switch havinga pivoted arm, a pivoted locing member supported in dependently of saidarm for mechanicallyy engaging and locking said arm in closed position,and electro-magnetic mechanism common to said arm and said member foractuating said arm and said member independ ently lof each other.

`5. A low voltage circuit breaker comprising a self-opening switchhaving an arm ivoted at one end, a movable locking mem- 'ier supportedindependently of said arm :xrranged to engage the free end of said armand. lock it in closed position, and a solenoid having a plungerconnected to said arm and an arma-ture connected to said locking member.

6. .A switch mechanism comprising a selfopemng switch including an armpivoted :it one end, and having a dog at its free end, a pivoted lockinglever supported independently of said arm arranged to engage said dogand mechanically lock said arm in closed position, and electro-magneticmechanism arranged to move said arm and said lever to interlockedposition.

7. A Switch mechanism comprising a selfopeninfr switch including an armpivoted at one end, and having a dog at its free end, a pivoted lockinglever arranged to engage said dog and mechanically lock said arm inclosed position, and electromagnetic mechanism arranged to move said armand said lever to interlocked position, in combination with normallyenergized electro-magnetic mechanism arranged to trip said lockresponsive to failure of current. .7 8. A low ,vo lt i circuit breakercomprising a. main switch; an electro-ma netic mechanism for closingsaid switch an conditioned for operation by closingV a branch circuitderiving current from the main cicuit; a movable lock for mechanicallylock. ing the main switch in closed position, and operated independentlyof the switch by the electro-magnet of said electro-magnet mechanism;and electro-magnetic mechaA nism in a normally closed branch circuit derivingr potential from said main circuit` for tripping said lock inresponse to voltage failure.

9. A low voltage circuit breaker compris ingr :1 self-opening mainSwitch; an electro magnetic mechanism loi' closing the switch includin fr a solenoid and a plunger Operatively connected to said switch: amechanical lock arranged to mechanically lock said main switch in closedposition and having an operating member constituting an armature of saidsolenoid: and normallv energized electro-magnetic imrchanism responsiveto variations in voltage on the main switch. for tripping said lock.conditioned t'or tripping operation bv failure ot line voltage on theclosed inain Switch.

ttt. lou' voltage circiiii breaker comprising a scllopcning main suitch: an electromagnetic mechanism for closing tbc switch includingr asolenoid and a plunger operatively connected to said switch: a movablelock arranged to mechanically lock said main switch in closed positionand having an operating member constituting an armature of saidsolenoid: a gravity-operated member for tripping said lock. an armatureconnected to said member normally to hold it in rar-.ed inactiveposition. and an electroinagnet associated \vith said armature andnoi-mall)P deriving current from the main circuit.

ll. A low voltage circuit breaker comprism;r a seltopeningr main switch,an eleclro-magnetic mechanism for closing the switch including asolenoid and a plunger operativetiv connected to said switch: a mov4able lock arranged to mechanically lock said main switch in closedposition and having an operating member eonst.itutin r an armature ofsaid solenoid: electro-magnetic mechanism having means. renderedoperative b v failure of current in the magnet. for trip pin,"Y saidlock; and supplemental switches for eontrolling r the operation of thefirstmentioned maiii-switch-operatng electromagnetic mechanismone switchbeing.v operated bv said mechanism and the other b v thesecond-mentioned electro-imlgnetic mechanism.

t2, circuit breaker comprising a sta tionary contact. anelectromagneticallyclosed self-opening;movable contact. and a mechanicallock for holdin;r the movable contact. in closed position. said lockincluding an element movable with the movable contact and a complementalmember mounted on a stationary part of the circuit breaker. one of saidelements beingr relativel'v movable. to permit the members to interlockon the closingY movement of said movable contact and the other memberbeing movable to permit the disengagement of said members.

tft. i circuit breaker comprising fixed and movable contacts adapted tocomplete and rupture :in electric circuit. :i support for tluI tixcdcontact. a movable -support l'oiV the iiimablt` contact. aiulcoiiipleineiital interlockingr members for inecliaiiicallv holdin;r

the movable support in circuit closed position` one of said membersbeing yielding relatively to the other to permit closingr movement otthe movable support and the other said member being movable to releasethe tirs-t said member and permit said inovable support to more tocireiiitopen position.

l-t. .i circuit breaker comprising ixed amt movable contacts adapted tocomplete and rupture an electric circuit1 a support for the fixedcontact` a movable support for the movable contact, complementalinterlocking members for mechanically holding,r the movable support incircuit closed position, and means by which one of said members ispositione or held rigidly against movement only during the closingmovement of the movable support.

la. circuit breaker comprising fixed and movable contacts adapted tocomplete and rupture an electric circuit, a support tor the fixedcontact, a movable support for the movable contact. complementalinterlocking members for mechanically holding the movable support incircuit closed position. means b v which one of said members ispositioned or held rigidly against move* ment only during the closingmovement of the movable support, and means for tripling said member torelease the other memiier and permit opening movement of said movablesupport.

t6. A circuit breaker comprising fixed and movable contacts adapted tocomplete and rupture an electric circuit, a support; for the fixedcontact, a. movable support for the movable contact, electromagneticmeans for moving said movable snp )ort to closed position` complementalinterlocking members for mechanically looking said movable support inclosed position, means by which one of said members moves or yields onlyto permit opening movement of the movable support and is held rigidlyagainst movement during the closing of' said movable support, and meansresponsive to voltage variation for tripping said member to permitopening movement of said movable support.

1T. A circuit breaker comprising fixed and movable contacts adapted tocomplete and rupture an electric circuit, a support for the. Fixedcontact, u. movable support for the movable contact. electromagneticmeans for moving said movable. support to closed position eomplementalinterlocking members for mechanically locking said movable support inclosed position` means by which one of said members moves or yields onlyto permit opening movement of the movable support aml is held rigidlyagainst movement during thc closing ot said movable support. meansresponsive to voltage. variation for tripping said member to permitoprlillfl lilo movement of said movable support, and means b v which theother interlocking mem. ber yields or moves during closing movement ofthe movable contact to permit the interengagcmcnt of said interlockingmembers.

1S. switch mechanism comprising fixed and movable contacts adapted tocomplete and rupture an electric circuit. a movable support. for tbemovable contact., a movable lock for mcclninically holding said supportin closed position. and means for rigidly positioning said lock onlyduring the closing movement ol' said movable support.

19. .5L switch mechanism comprising fixed and movable contacts adaptedto rupture or complete an electric circuit` a stationary support for thetixed contact, a movable support for the movable contact, interlockinginembexs mounted on said supports respectivclv for holding the contactsin closed position, one of said members being movable irlatively to theother to permit their engagfement and said other member being movableonly to permit their disengagemente and means responsive to voltagevariations in said circuit for tripping said lastancntioncd member.

20. A switch mechanism comprising fixed and movable contacts adapted torupture or complete an electric circuit, a stationary support for thefixed contact, a movable snpport for the movable contact, interlockingmembers mounted on said supports respectively for holdingr t-he contactsin closed position, one of said members being movable relatively to theother to permit their engagement and said other member being movableonly to permit their disengagement, means responsive to .voltagevariations in said circuit for tripping said last-mentioned member, andmeans by which said last-men tionen member is held against movementduring only tbe closing movement of said movable support.

2l, A switch mechanism comprising a lxcd cont-act, a movable contactlnonnted to move in the are of a circle between contactclosed andcontact-open positions for complcting or rupturiug an electric` circuit,means for causing such movcmcnt,`a lock to mechanically lock saidmovable contact in switch-closed position and an electromagnetic deviceresponsive to voltage variations in said circuit for controlling thesaid means when energiaed and for tripping said lock when deenergized.

.22. switch mechanism comprising a stationary support, a fixed Contactthereon, a movable arm. a movable contact thereon, said contacts beingradapted to rnptnrc or complete n working circuit, :in vlrrlronnig notfor moving said arm from open lo closed position. interlockingr members.one sup ported b v said stationary support and the other supported byand movable with said arm for mechanically holding said arm in closedposition, one of said members being yielding relatively to the other topermit their engagement, and said other member being movable to permittheir disengagement, and an electromagnetic device for closing a circuitthrough the first-mentioned electromagnet when energized, and fortrippingr said last-mentioned interlocking member when deenergized 23.switch mechanism comprisingr a stationary support having a stationarycontact, a movable arm having a movable contact, a lock movably mountedon said stationary support, a yielding dog carried by said arm adaptedto engage said lock and to yield relatively thereto during closingrmovement of said arm, means for holding said lock against movementduring said closing movement of said arm, and an electromagneti call7controlled device for tripping said lock relatively to 'said dog topermit opening movement of said arm.

24. A circuit breaker comprising a switch, means urging said switch toopen position, complemental interlocking members for holding said switchclosed, means acting only during the closing movement of said switch forurging one of said members to locking position. and means for movingsaid member out of locking position to cause the switch to open.

25. A circuit breaker comprising a switch, means urging said switch toopen position, complementa! interlocking members for holding said switchclosed, electromagnetic meansv acti A only during `the closing movementof sai switch-for urging'one of said members to locking position, andmeans for moving said member out of locking position to cause the switchto open.

26. A circuit breaker comprising a switch, means urging said switch toopen position, complemental interlockingr members for holding saidswitch closed, means acting only duringr the closing movement of saidSnitch for urging one of said members to locking position, and meansacting on loss of'line potential for moving said member out oflockingposition.

2.- A circuit lJ'reaker comprising a switch, means urging said switch toopen position, complemental interlocking members for holding said switchclosed, means acting only during the closing movement of said switch forurging one of said members to locking position. and an electromagnetsubjected to line. voltage effective on its de-energization to move saidmember out of lorking position.

9H. circuit breaker comprising :i switch. means urging said switch toopen position. omplemental interlocking membcis for holdingY said switchclosed, nouns acting only during the closing movement of said switch forurging one of said members to locking position, means for movingr saidmember ont of locking position, and an electromagnet for holding;r saidmoving means inoperative.`

29. A circuit breaker comprising,r a switch, means urgingT said switchto open position, complement-al interlocking members for holdingr saidswitch closed, means acting: only during the closing movement of saidswitclrfor urging one of said members to locking: position, means formoving said member ont of locking;r position, and anelectromagnetsubjected to line potential energizable to hold said means inoperative.

30. A circuit breaker comprising a switch, means urging said switch toopen position, complementa] interlocking,r members for holdingr saidswitch in closed position, electromagnetic means for closing said switchand moving one of said members into locking position, means acting to(le-energize said electromagnetic means when said switch closes. andmeans for moving said member ont of said locking position to ranse saidswitch to open.

3l. A circuit breaker comprising a switch,

means urgingy said switch to open position, complemental interlockingmembers for holding said switch in closed position, electromagneticmeans for closing said switch and moving one of said members intolocking position. means acting to (1e-energize said electromagneticmeans when said switch closes. and means acting on failure of linepotential to move said member ont of lockingr position to canse saidswitch to open.

circuit breaker comprising a switch, means urging said switch to openposition. coniplemental interlockingr members, one of said memberscomprisingr a lever, for holdingl said switch in closed position,electromagnetic means for closing said switch and for moving said leverto lockingr position. means acting,r to cle-energize saidelectromagnetic means when said switch closes, a solenoid subjected toline potential` and an armature for said solenoid acting oncle-energization of said solenoid to impinge on said lever and move itont ot locking position to canse said witch to open.

In testimony wiereof l have aliixed my signature.

ERNEST (il. JOHNSON.

